Find the total number of ores in which the roasting process is used in the metallurgy of the corresponding metal: galena, haematite, calamine, cinnabar, horn silver, limestone

Roasting process:- In the metallurgical process of roasting, the ore is heated below its melting point in the presence of extra air and transformed into its oxide. While roasting is a technique used to transform sulfide ores, calcination is mostly used to oxidize carbonates.

The roasting process is used in the metallurgy of the following metals:

galena $\to$$\mathrm{PbS}$

haematite $\to$ ${\mathrm{Fe}}_2{\mathrm{O}}_3$

zinc blende $\to$$\mathrm{ZnS}$

cinnabar $\to$$\mathrm{HgS}$